*{
	padding: 0;
	margin: 0;
}
.header,.footer{
	height: 50px;
	background-color: #cdcdcd;
}
.footer{
	position: absolute;/*脱离文档流*/
	bottom: 0px;
	width: 100%;/*设置宽度*/
	line-height: 50px;/*让行高等于容器高度*/
	text-align: center;
}
.footer>span{
	line-height: 50px;
}
ul{
	line-height: 50px;
}
ul>li{
	list-style-type: none;
	display: inline-block;
	line-height: 50px;
	margin: 0px 10px 0px 10px;
	text-align: center;
}
a{
	color: blue;
	text-decoration: none;
}
.menu{
	color: red;
	width: 100px;
	position: relative;
}
.menu>ul{
	display: none;
}
.menu:hover>ul{
	display: block;
	position: absolute;
}
.title{
	padding: 50px;
	text-align: center;
}

form>table{
	margin: auto;
	text-align: center;
	margin-bottom: 100px;
}
table input[type="text"],
table input[type="password"]{
	width: 250px;
}
table input[type="submit"],
table input[type="button"]{
	width: 100px;
	height: 25px;
}